Electro-optical device and electronic apparatus

ABSTRACT

In an electro-optical device, a light shielding layer is provided at a first substrate between a second capacitance electrode and a second interlayer insulating layer, in a layer between the second capacitance electrode of a capacitance element and the pixel electrode. The light shielding layer includes a first portion stacked on the second capacitance electrode, and a second portion that protrudes from an end portion of the first portion, through a side of the first capacitance electrode of the capacitance element, toward both sides in a width direction of a semiconductor layer.

The present application is based on, and claims priority from JP Application Serial Number 2020-127097, filed Jul. 28, 2020, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND 1. Technical Field

The present disclosure relates to an electro-optical device that includes, between a transistor and a pixel electrode, a light shielding layer that inhibits incidence of light on a semiconductor layer, and to an electronic apparatus.

2. Related Art

An electro-optical device used as a light valve or the like of a projection-type display device is provided with a semiconductor layer between a substrate body and the pixel electrode, and a transistor is configured using the semiconductor layer. In such an electro-optical device, structure has been proposed in which, in a capacitance element provided between a transistor and a pixel electrode, by protruding an end portion of the capacitance electrode on an upper layer side toward the semiconductor layer side, incidence of light on the semiconductor layer is suppressed (see JP 2001-66633 A).

The capacitance element has structure in which a capacitance electrode on a lower layer side, a thin dielectric film, and a capacitance electrode on an upper layer side are stacked, and thus as the structure described in JP 2001-66633 A, when an end portion of the capacitance electrode on the upper layer side is extended toward a side of the capacitance electrode on the lower layer side when a dielectric film is not present on a side of the capacitance electrode on the lower layer side, there is a possibility that the capacitance electrode on the upper layer side and the capacitance electrode on the lower layer side may be short-circuited. In addition, even when the end portion of the capacitance electrode on the lower layer side, the dielectric film, and the end portion of the capacitance electrode on the upper layer side are all extended toward the semiconductor layer side, the dielectric film is not appropriately formed at a portion facing the semiconductor layer, thus there is a possibility that the capacitance electrode on the upper layer side and the capacitance electrode on the lower layer side may be short-circuited. Therefore, there is a problem that it is difficult to suppress incidence of light on the semiconductor layer by a light shielding layer provided between the transistor and the pixel electrode while avoiding problems such as a short circuit.

SUMMARY

In order to solve the above-described problem, an aspect of an electro-optical device according to the present disclosure includes a substrate body, a pixel electrode, a transistor including a semiconductor layer in a layer between the substrate body and the pixel electrode, a capacitance element including a first capacitance electrode overlapping with the semiconductor layer, the capacitance element being in a layer between the first interlayer insulating layer and the pixel electrode, and a second capacitance electrode overlapping with the first capacitance electrode via a dielectric film, the second capacitance electrode being in a layer between the first capacitance electrode and the pixel electrode, and a light shielding layer that includes a first portion overlapping with the second capacitance electrode between the second capacitance electrode and the pixel electrode, and a second portion protruding from an end portion in a second direction intersecting the first direction of the first portion, through a side of the first capacitance electrode toward the substrate body side, the first portion being electrically coupled to the second capacitance electrode.

An electro-optical device to which the present disclosure is applied is used for a variety of electronic apparatuses. In the present disclosure, when an electronic apparatus is a projection-type display device, the projection-type display device is provided with a light source unit configured to emit light to be supplied to an electro-optical device, and a projection optical system configured to project light modulated by the electro-optical device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an electro-optical device according to Exemplary Embodiment 1 of the present disclosure.

FIG. 2 is a cross-sectional view of the electro-optical device illustrated in FIG. 1.

FIG. 3 is a plan view of a plurality of pixels adjacent to each other in the electro-optical device illustrated in FIG. 1.

FIG. 4 is an enlarged plan view illustrating one of the pixels illustrated in FIG. 3.

FIG. 5 is an A1-A1′ cross-sectional view of FIG. 4.

FIG. 6 is a B1-B1′ cross-sectional view of FIG. 4.

FIG. 7 is a C1-C1′ cross-sectional view of FIG. 4.

FIG. 8 is a plan view of a scan line, a semiconductor layer, a gate electrode, and the like illustrated in FIG. 4.

FIG. 9 is a plan view of a first capacitance electrode, a second capacitance electrode, and the like illustrated in FIG. 4.

FIG. 10 is a plan view of a data line, a capacitance line, and the like illustrated in FIG. 4.

FIG. 11 is an enlarged plan view illustrating a periphery of a contact hole illustrated in FIG. 8.

FIG. 12 is an explanatory diagram of an electro-optical device according to Exemplary Embodiment 2 of the present disclosure.

FIG. 13 is an A2-A2′ cross-sectional view of FIG. 12.

FIG. 14 is a B2-B2′ cross-sectional view of FIG. 12.

FIG. 15 is a C2-C2′ cross-sectional view of FIG. 12.

FIG. 16 is a schematic configuration view of a projection-type display device using an electro-optical device to which the present disclosure is applied.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the disclosure will be described below with reference to the drawings. Note that, in each of the figures to be referred to in the following description, to illustrate each layer, each member, and the like in a recognizable size in the drawings, each layer, each member, and the like are illustrated at a different scale. Moreover, in the description described below, when each layer formed at a first substrate 10 is described, an upper layer side or a front surface side means a side (a side on which a second substrate 20 is located) opposite to a side on which a substrate body 19 is located, and a lower layer side means a side on which the substrate body 19 is located. In addition, of two intersecting directions among in-plane directions of the first substrate 10, a direction in which a scan line 3 a extends is a first direction X, and a direction in which a data line 6 a extend is a second direction Y. In addition, one side in a direction along the second direction Y is one side Y1 in the second direction Y, another side in the direction along the second direction Y is another side Y2 in the second direction Y, one side in a direction along the first direction X is one side X1 in the first direction X, and another side in the direction along the first direction X is another side X2 in the first direction X.

Exemplary Embodiment 1 1. Configuration of Electro-optical Device 100

FIG. 1 is a plan view of an electro-optical device 100 according to Exemplary Embodiment 1 of the present disclosure. FIG. 2 is a cross-sectional view illustrating the electro-optical device 100 illustrated in FIG. 1. As illustrated in FIG. 1 and FIG. 2, in the electro-optical device 100, the first substrate 10 and the second substrate 20 are bonded together with a sealing material 107 creating a predetermined gap, where the first substrate 10 is opposed to the second substrate 20. The sealing material 107 is provided in a frame-like shape in conformance with the outer edge of the second substrate 20. An electro-optical layer 80 such as a liquid crystal layer is provided in an area surrounded by the sealing material 107 between the first substrate 10 and the second substrate 20. The seal material 107 is a photocurable adhesive, or a photocurable and thermosetting adhesive, and a gap material such as glass fiber or glass beads for setting a distance between the substrates to a predetermined value is compounded in the sealing material 107. In the present exemplary embodiment, the first substrate 10 and the second substrate 20 both have a quadrangle shape, and in a substantially central portion of the electro-optical device 100, a display region 10 a is provided as a quadrangle region. In accordance with such a shape, the sealing material 107 is also provided in a substantially quadrangular shape, and a peripheral region 10 b having a rectangular frame shape is provided between an inner peripheral edge of the sealing material 107 and an outer peripheral edge of the display region 10 a.

The first substrate 10 includes a substrate body 19 formed of a transmissive substrate such as a quartz substrate or a glass substrate. On one surface 19 s side of the substrate body 19 on the second substrate 20 side, on an outer side of the display region 10 a, a data line driving circuit 101 and a plurality of terminals 102 are formed along one side of the first substrate 10. A scan line driving circuit 104 is formed along other sides adjacent to the one side. Although not illustrated, a flexible wiring substrate is coupled to the terminals 102, and various kinds of potential and various signals are input to the first substrate 10 via the flexible wiring substrate.

The display region 10 a on the one surface 19 s of the substrate body 19 is formed, in a matrix pattern, with a plurality of transmissive pixel electrodes 9 a made from an Indium Tin Oxide (ITO) film. A first orientation film 16 is formed on the second substrate 20 side with respect to the pixel electrodes 9 a, and the pixel electrodes 9 a are covered with the first orientation film 16.

The second substrate 20 includes a substrate body 29 formed of a transmissive substrate such as a quartz substrate or a glass substrate. On one surface 29 s side, which faces the first substrate 10, of the substrate body 29, a transmissive common electrode 21 including, for example an ITO film or the like, is formed. A second orientation film 26 is formed on the first substrate 10 side with respect to the common electrode 21. The common electrode 21 is formed over substantially the entire surface of the second substrate 20, and is covered with the second orientation film 26. At the second substrate 20, a light shielding layer 27 having a light-shielding property and including resin, metal, or a metal compound is formed between the substrate body 29 and the common electrode 21. A transmissive protective layer 28 is formed between the light-shielding layer 27 and the common electrode 21. The light shielding layer 27 is formed, for example, as a partition 27 a in a frame-like shape extending along the outer peripheral edge of the display region 10 a. The light-shielding layer 27 is also formed as a light shielding layer 27 b constituting a black matrix in regions overlapping in plan view with regions each located between the pixel electrodes 9 a adjacent to each other. Regions overlapping, when viewed in plan view, with the partition 27 a in the peripheral region 10 b of the first substrate 10 are formed with dummy pixel electrodes 9 b formed simultaneously with the pixel electrodes 9 a. Note that, a lens may be provided at the second substrate 20 at a position facing the pixel electrode 9 a, and in this case, the light shielding layer 27 b is often not formed.

Any of the first orientation film 16 and the second orientation film 26 is an inorganic orientation film including a diagonally vapor-deposited film of SiOx (x<2), SiO2, TiO2, MgO, Al2O3, and the like, for example, and liquid crystal molecules having negative dielectric anisotropy used for the electro-optical layer 80 are tilt-oriented. Therefore, the liquid crystal molecules form a predetermined angle with respect to the first substrate 10 and the second substrate 20. In this way, the electro-optical device 100 is constituted as a liquid crystal device of a Vertical Alignment (VA) mode.

The first substrate 10 includes an inter-substrate conduction electrode 109 being formed in a region positioning outside the sealing material 107 and overlapping with a corner portion of the second substrate 20 such that electrical conduction is established between the first substrate 10 and the second substrate 20. An inter-substrate conduction material 109 a including conductive particles is disposed in the inter-substrate conduction electrode 109. The common electrode 21 of the second substrate 20 is electrically coupled to the first substrate 10 side via the inter-substrate conduction material 109 a and the inter-substrate conduction electrode 109. Therefore, common potential is applied to the common electrode 21 from the first substrate 10 side.

In the electro-optical device 100, the pixel electrodes 9 a and the common electrode 21 are formed of a transmissive conductive film such as an ITO film, and the electro-optical device 100 is constituted as a transmissive liquid crystal device. In the electro-optical device 100, of the first substrate 10 and the second substrate 20, light that is incident to the electro-optical layer 80 from either one of the substrates is modulated while passing through the other substrate and being emitted, and displays an image. In the present exemplary embodiment, the electro-optical device 100 displays an image by the light incident from the second substrate 20 being modulated by the electro-optical layer 80 for each of the pixels while passing through the first substrate 10 and being emitted, as indicated by an arrow L.

2. Schematic Configuration of Pixels

FIG. 3 is a plan view of the plurality of pixels adjacent to each other in the electro-optical device 100 illustrated in FIG. 1. FIG. 4 is an enlarged plan view illustrating one of the pixels illustrated in FIG. 3, and in FIG. 4, a vicinity of a transistor 30 is enlarged and illustrated. FIG. 5 is the A1-A1′ cross-sectional view of FIG. 4. FIG. 6 is the B1-B1′ cross-sectional view of FIG. 4. FIG. 7 is the C1-C1′ cross-sectional view of FIG. 4. Note that, in FIG. 3 and FIG. 4, and FIG. 8 to FIG. 10 to be described later, layers are indicated by the lines below. Further note that in FIG. 3 and FIG. 4, and FIG. 8 to FIG. 10 described below, respective positions of end portions are shifted, for layers whose end portions are mutually overlapped in plan view, to make a shape and the like of the layer easily recognizable. In addition, a contact hole 41 g is illustrated with a region hatched with oblique lines raising to the right.

A scan line 3 a=a thick alternate long and short dash line

A semiconductor layer 31 a=a thin and short broken line

A gate electrode 8 a=a thin solid line

A first capacitance electrode 4 a=a thin and long dashed line

A second capacitance electrode 5 a=a thin alternate long and short dash line

A light shielding layer 2 a=a thick solid line The data line 6 a and relay electrodes 6 b and 6 c=thick and long dashed lines

A capacitance line 7 a and a relay electrode 7 b=thick two-dot chain lines

The pixel electrode 9 a=a thick short dashed line

As illustrated in FIG. 3 and FIG. 4, the pixel electrode 9 a is formed at each of the plurality of pixels on a surface of the first substrate 10 facing the second substrate 20, where the scan line 3 a, the data line 6 a, and the capacitance line 7 a extend along an inter-pixel region between the pixel electrodes 9 a adjacent to each other. The data line 6 a extends in the second direction Y in the inter-pixel region. The scan line 3 a extends in the first direction X in the inter-pixel region. The capacitance line 7 a extends along the second direction Y and the first direction X in the inter-pixel region. Further, the transistor 30 is formed corresponding to an intersection between the data line 6 a and the scan line 3 a. Here, the scan line 3 a, the data line 6 a, and the capacitance line 7 a each have a light shielding property. Accordingly, a region in which the scan line 3 a, the data line 6 a, the capacitance line 7 a, and an electrode in the same layer as these wiring lines are formed is a light shielding region 18 through which light does not transmit, and a region surrounded by the light shielding region 18 is an aperture region 17 through which light transmits.

As illustrated in FIG. 5, FIG. 6, and FIG. 7, the first substrate 10 includes the transistor 30 including the semiconductor layer 31 a in a layer between the substrate body 19 and the pixel electrode 9 a, a first interlayer insulating layer 42 provided in a layer between the transistor and the pixel electrode 9 a, and a capacitance element 55, the capacitance element 55 includes a first capacitance electrode 4 a overlapping with the semiconductor layer 31 a in a layer between a first interlayer insulating layer 42 and the pixel electrode 9 a, and a second capacitance electrode 5 a overlapping with the first capacitance electrode 4 a via a dielectric film 40 in a layer between the first capacitance electrode 4 a and the pixel electrode 9 a. In the first substrate 10, the scan line 3 a extends in the first direction X in a layer between the substrate body 19 and the semiconductor layer 31 a, and the data line 6 a extends in the second direction Y in a layer between the second capacitance electrode 5 a and the pixel electrode 9 a. Further, an interlayer insulating layer 41, the first interlayer insulating layer 42, a second interlayer insulating layer 43, and an interlayer insulating layers 44 and 45 are stacked in order between the substrate body 19 and the pixel electrode 9 a. The first interlayer insulating layer 42, the second interlayer insulating layer 43, and the interlayer insulating layers 41, 44, and 45 each include a transmissive insulating film such as silicon oxide. In the present exemplary embodiment, a surface on the pixel electrode 9 a side of each of the second interlayer insulating layer 43, the interlayer insulating layers 44, and 45 is formed as a continuous plane by chemical mechanical polishing or the like.

3. Detailed Description of Each Layer

A detailed configuration of the first substrate 10 will be described with reference FIG. 5, FIG. 6, and FIG. 7, while referring to FIG. 8 to FIG. 10 described below as necessary. FIG. 8 is a plan view of the scan line 3 a, the semiconductor layer 31 a, the gate electrode 8 a, and the like illustrated in FIG. 4. FIG. 9 is a plan view of the first capacitance electrode 4 a, the second capacitance electrode 5 a, and the like illustrated in FIG. 4. FIG. 10 is a plan view illustrating the data line 6 a, the capacitance line 7 a, and the like illustrated in FIG. 4. Note that, FIG. 8 to FIG. 10 each illustrate a contact hole related to electrical coupling of the electrodes and the like illustrated in those drawings, and each illustrate the semiconductor layer 31 a and the pixel electrode 9 a for indicating a position to be referenced.

First, as illustrated in FIG. 5, FIG. 6, and FIG. 7, in the first substrate 10, the scan line 3 a extending along the first direction X is formed between the substrate body 19 and the interlayer insulating layer 41. The scan line 3 a is formed of a light shielding conductive film such as a metal silicide film, a metal film, or a metal compound film. In the present exemplary embodiment, the scan line 3 a is formed of tungsten silicide (WSi), tungsten, or titanium nitride.

Between the interlayer insulating layer 41 and the first interlayer insulating layer 42 is formed the transistor 30 for pixel switching. The transistor 30 includes the semiconductor layer 31 a formed at a surface of the interlayer insulating layer 41 on an opposite side to the substrate body 19, a gate insulating film 32 stacked on the pixel electrode 9 a side of the semiconductor layer 31 a, and the gate electrode 8 a overlapping in plan view with the semiconductor layer 31 a on the pixel electrode 9 a side of the gate insulating film 32. The semiconductor layer 31 a includes, for example, a polysilicon film. The gate insulating film 32 has two-layer structure including a first gate insulating film 32 a including a silicon oxide film that is obtained by thermally oxidizing the semiconductor layer 31 a, and a second gate insulating film 32 b including a silicon oxide film that is formed by using, for example, a low-pressure CVD method. The gate electrode 8 a is formed of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal compound film.

The contact hole 41 g for electrically coupling the scan line 3 a and the gate electrode 8 a of the transistor 30 is provided in the interlayer insulating layer 41. A detailed configuration of such a contact hole 41 g will be described below with reference to FIG. 11.

As illustrated in FIG. 8, the scan line 3 a extends linearly along the first direction X with the same width dimension. The semiconductor layer 31 a extends from an intersecting portion of the scan line 3 a and the data line 6 a to the other side X2 in the first direction X, and overlaps with the scan line 3 a in plan view. A portion of the semiconductor layer 31 a overlapping in plan view with the gate electrode 8 a is a channel region 31 c. In the present exemplary embodiment, the transistor 30 has lightly doped drain (LDD) structure. Accordingly, in the semiconductor layer 31 a, a data line side source drain region 31 s on the one side X1 in the first direction X in which the data line 6 a is positioned with respect to the channel region 31 c includes a first region 31 t spaced apart from the channel region 31 c, and a first low concentration region 31 u sandwiched between the first region 31 t and the channel region 31 c, and the first low concentration region 31 u has a lower impurity concentration than that of the first region 31 t. In addition, in the semiconductor layer 31 a, a pixel electrode side source drain region 31 d on the other side X2 in the first direction X opposite to the data line 6 a with respect to the channel region 31 c includes a second region 31 e spaced apart from the channel region 31 c, and a second low concentration region 31 f sandwiched between the second region 31 e and the channel region 31 c, and the second low concentration region 31 f has a lower impurity concentration than that of the second region 31 e.

The gate electrode 8 a includes a first electrode portion 8 a 0 extending in the second direction Y so as to overlap in plan view with the semiconductor layer 31 a via the gate insulating film 32, and second electrode portions 8 a 1 and 8 a 2 extending in the first direction X along the semiconductor layer 31 a from respective end portions on both sides of the first electrode portion 8 a 0 in the second direction Y on both sides in the second direction y of the semiconductor layer 31 a, and the second electrode portions 8 a 1 and 8 a 2 do not overlap in plan view with the semiconductor layer 31 a.

In FIG. 5, FIG. 6, and FIG. 7, the capacitance element 55 is provided in which the first capacitance electrode 4 a, the dielectric film 40, and the second capacitance electrode 5 a are stacked in order, between the first interlayer insulating layer 42 and the second interlayer insulating layer 43 on an upper layer side of the transistor 30. The capacitance element 55 is a retention capacitor that prevents a fluctuation in an image signal retained by a liquid crystal capacitor configured between the pixel electrode 9 a of the first substrate 10 and the common electrode 21 of the second substrate 20. The first capacitance electrode 4 a and the second capacitance electrode 5 a are each formed of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal compound film. In the present exemplary embodiment, the first capacitance electrode 4 a and the second capacitance electrode 5 a are each a conductive polysilicon film.

As illustrated in FIG. 9, the first capacitance electrode 4 a includes a body portion 4 a 1 that extends in the first direction X so as to overlap in plan view with the scan line 3 a and the semiconductor layer 31 a, and a protruding portion 4 a 2 that protrudes from the body portion 4 a 1 so as to overlap in plan view with the data line 6 a, and an end portion of the body portion 4 a 1 is electrically coupled to the second region 31 e of the semiconductor layer 31 a via a contact hole 42 a formed in the first interlayer insulating layer 42. Of the semiconductor layer 31 a, the first capacitance electrode 4 a has a notch 4 a 3 formed so as to not overlap with an end portion overlapping with the data line 6 a in plan view.

The second capacitance electrode 5 a includes a body portion 5 a 1 that overlaps with a body portion 5 a 1 of the first capacitance electrode 4 a in plan view, and a protruding portion 5 a 2 that overlaps with the protruding portion 4 a 2 of the first capacitance electrode 4 a in plan view. Accordingly, the capacitance element 55 includes a first element portion 551 extending in the first direction X so as to overlap with the semiconductor layer 31 a, and a second element portion 552 that extends in the second direction Y so as to overlap with the data line 6 a from an intersecting portion of the first element portion 551 and the data line 6 a. In addition, the second capacitance electrode 5 a, similar to the first capacitance electrode 4 a, has a notch 4 a 3 formed in the semiconductor layer 31 a so as not to overlap with an end portion overlapping with the data line 6 a in plan view. Also, a notch 5 a 4 is formed in an end portion of the body portion 5 a 1 of the second capacitance electrode 5 a on the other side X2 in the first direction X, so as not to overlap with an end portion of the body portion 4 a 1 of the first capacitance electrode 4 a.

In FIG. 5, FIG. 6, and FIG. 7, the interlayer insulating layers 44 and 45 are formed on an upper layer side of the second interlayer insulating layer 43. The data line 6 a and the relay electrodes 6 b and 6 c are provided in an interlayer between the second interlayer insulating layer 43 and the interlayer insulating layer 44. The data line 6 a, and the relay electrodes 6 b and 6 c are each formed of the same conductive film. Any of the data line 6 a, the relay electrodes 6 b, and 6 c includes a light shielding conductive film such as a metal silicide film, a metal film, or a metal compound film. For example, the data line 6 a, the relay electrodes 6 b, and 6 c are each formed by multilayer structure of titanium layer/titanium nitride layer/aluminum layer/titanium nitride layer, or multilayer structure of titanium nitride layer/aluminum layer/titanium nitride layer.

A contact hole 43 a is provided in the first interlayer insulating layer 42 and the second interlayer insulating layer 43, and the contact hole 43 a extends through the gate insulating film 32, the first interlayer insulating layer 42, and the second interlayer insulating layer 43. The data line 6 a is electrically coupled to the first region 31 t via the contact hole 43 a. The contact hole 43 a is formed in a portion corresponding to the notch 4 a 3 of the first capacitance electrode 4 a, and the notch 5 a 3 of the second capacitance electrode 5 a described with reference to FIG. 9. Accordingly, the contact hole 43 a and the capacitance element 55 can be separated. A contact hole 43 b is provided in the second interlayer insulating layer 43, and the contact hole 43 b extends through the second interlayer insulating layer 43. The relay electrode 6 b is electrically coupled to the first capacitance electrode 4 a via a contact hole 43 b. The contact hole 43 b is formed in a portion corresponding to the notch 5 a 4 of the second capacitance electrode 5 a described with reference to FIG. 9. A contact hole 43 c is provided in the second interlayer insulating layer 43, and the relay electrode 6 c is electrically coupled to the second capacitance electrode 5 a via a contact hole 43 c. The relay electrode 6 c covers at least from the first low concentration region 31 u to the second low concentration region 31 f of the semiconductor layer 31 a from the pixel electrode 9 a side.

In the present exemplary embodiment, as described below, the first substrate 10 includes the conductive light shielding layer 2 a including a first portion 2 a 1 that overlaps with a surface of the second capacitance electrode 5 a on the pixel electrode 9 a side. Further, the relay electrode 6 c is electrically coupled to the light shielding layer 2 a via the contact hole 43 c, and is electrically coupled to the second capacitance electrode 5 a via the light shielding layer 2 a. The light shielding layer 2 a further includes a second portion 2 a 2 for increasing a light shielding property.

The capacitance line 7 a and the relay electrode 7 b are provided in an interlayer between the interlayer insulating layer 44 and the interlayer insulating layer 45. The capacitance line 7 a and the relay electrode 7 b are each formed of the same conductive film. Any of the capacitance line 7 a, and the relay electrode 7 b includes a light shielding conductive film such as a metal silicide film, a metal film, or a metal compound film. For example, the capacitance line 7 a, and the relay electrode 7 b are each formed by multilayer structure of titanium layer/titanium nitride layer/aluminum layer/titanium nitride layer, or multilayer structure of titanium nitride layer/aluminum layer/titanium nitride layer.

A contact hole 44 c is provided in the interlayer insulating layer 44, and the capacitance line 7 a is electrically coupled to the relay electrode 6 c via the contact hole 44 c. Therefore, the capacitance line 7 a is electrically coupled to the second capacitance electrode 5 a via the relay electrode 6 c, and a constant potential, such as common potential, is applied to the second capacitance electrode 5 a from the capacitance line 7 a. A contact hole 44 b is provided in the interlayer insulating layer 44, and the relay electrode 7 b is electrically coupled to the relay electrode 6 b via the contact hole 44 b.

A contact hole 45 a is formed in the interlayer insulating layer 45, and the pixel electrode 9 a is electrically coupled to the relay electrode 7 b via the contact hole 45 a. Thus, the pixel electrode 9 a is electrically coupled to the first capacitance electrode 4 a via the relay electrodes 7 b and 6 b. Here, since the first capacitance electrode 4 a is electrically coupled to the second region 31 e via the contact hole 42 a, the pixel electrode 9 a is electrically coupled to the second region 31 e via the first capacitance electrode 4 a.

4. Configuration around Contact Hole 41 g

FIG. 11 is an enlarged plan view illustrating a periphery of the contact hole 41 g illustrated in FIG. 8. The gate electrode 8 a is formed by stacking a polysilicon film 81 a and a light shielding layer 82 a. In FIG. 11, the polysilicon film 81 a is hatched with oblique lines lowering to the right, and the light shielding layer 82 a is hatched with oblique lines rising to the right. Therefore, a region hatched with oblique lines lowering to the right and oblique lines rising to the right indicates that the polysilicon film 81 a and the light shielding layer 82 a are stacked.

As illustrated in FIG. 11, the contact hole 41 g extends along the first direction X on both sides of the semiconductor layer 31 a, and overlaps with both the gate electrode 8 a and the scan line 3 a in plan view. Accordingly, the gate electrode 8 a is electrically coupled to the scan line 3 a via the contact hole 41 g, and thus a scanning signal is applied from the scan line 3 a.

The contact hole 41 g is provided at least along the second low concentration region 31 f. In the present exemplary embodiment, the contact hole 41 g extends at least from both sides of the first low concentration region 31 u, through both sides of the channel region 31 c, to both sides of the second low concentration region 31 f.

In the present exemplary embodiment, the gate electrode 8 a is configured by stacking the conductive polysilicon film 81 a extending in the second direction Y so as to intersect the semiconductor layer 31 a, and the light shielding layer 82 a covering the polysilicon film 81 a. The light shielding layer 82 a is formed from a material having a higher light shielding property than that of the polysilicon film 81 a. For example, the light shielding layer 82 a is formed from a light shielding conductive film such as tungsten silicide.

The light shielding layer 82 a is formed over a wider area than the polysilicon film 81 a, and covers the entire polysilicon film 81 a. Therefore, in a region in the gate electrode 8 a where the polysilicon film 81 a is formed, the polysilicon film 81 a and the light shielding layer 82 a are formed in two-layer structure, and in a region in the gate electrode 8 a where the polysilicon film 81 a is not formed, the light shielding layer 82 a is formed in single layer structure. For example, in the gate electrode 8 a, the polysilicon film 81 a is not formed inside the contact hole 41 g, and the light shielding layer 82 a is formed in single layer structure. Accordingly, the light shielding layer 82 a is provided along an entire side surface of the contact hole 41 g. In contrast, of the first electrode portion 8 a 0 extending in the second direction Y in the gate electrode 8 a, in a portion outside the contact hole 41 g, the polysilicon film 81 a and the light shielding layer 82 a is formed in two-layer structure.

Such a configuration is achieved by the following processes. First, the scan line 3 a, the interlayer insulating layer 41, the semiconductor layer 31 a, and the gate insulating film 32 are formed. Next, after a conductive polysilicon film is formed, the polysilicon film is patterned to form the polysilicon film 81 a extending in the second direction Y intersecting the semiconductor layer 31 a.

Next, with an etching mask formed, the polysilicon film 81 a and the interlayer insulating layer 41 are etched to form the contact hole 41 g. Therefore, the polysilicon film 81 a is not present inside the contact hole 41 g. Next, after a light shielding layer is formed, the light shielding layer is patterned to form the light shielding layer 82 a, as illustrated in FIG. 10.

5. Light Shielding by Light Shielding Layer 2 a

As illustrated in FIG. 5, FIG. 6, FIG. 7, and FIG. 9, in the first substrate 10, the conductive light shielding layer 2 a including the first portion 2 a 1 that overlaps with the second capacitance electrode 5 a is provided between the second capacitance electrode 5 a and the second interlayer insulating layer 43, in a layer between the first element portion 551 of the second capacitance electrode 5 a and the pixel electrode 9 a. The light shielding layer 2 a is formed of a light shielding conductive film such as a metal silicide film, a metal film, or a metal compound film.

In the present exemplary embodiment, the light shielding layer 2 a includes the second portion 2 a 2 that protrudes from an end portion of the first portion 2 a 1 that overlaps with the second capacitance electrode 5 a, at least separated from the first capacitance electrode 4 a, along a side surfaces of the second capacitance electrode 5 a and the first capacitance electrode 4 a, toward the semiconductor layer 31 a side. As illustrated in FIG. 7, at least the light shielding layer 2 a includes the second portion 2 a 2 that protrudes from an end portion of the first portion 2 a 1 in the second direction Y, toward both sides in a width direction of the semiconductor layer 31 a through a side of the second capacitance electrode 5 a and the first capacitance electrode 4 a.

The first portion 2 a 1 is stacked on a surface of the second capacitance electrode 5 a on the pixel electrode 9 a side, and is electrically coupled to the second capacitance electrode 5 a. Here, an insulating film 47 covering the side surface of the first capacitance electrode 4 a is provided at the first substrate 10, and the second portion 2 a 2 overlaps with the insulating film 47 from a side opposite the first capacitance electrode 4 a. In the present exemplary embodiment, the insulating film 47 is a side wall that does not overlap with the second capacitance electrode 5 a in plan view, and covers the side surface of the first capacitance electrode 4 a and a side surface of the dielectric film 40 between the first interlayer insulating layer 42 and the second interlayer insulating layer 43, and the second portion 2 a 2 overlaps with the insulating film 47 from a side opposite the first capacitance electrode 4 a. Further, an end portion of the second portion 2 a 2 protrudes from a surface 4 a 0 on the semiconductor layer 31 a side of the first capacitance electrode 4 a toward the semiconductor layer 31 a side.

In a manufacturing process of the electro-optical device 100 having such structure, the first capacitance electrode 4 a, the dielectric film 40, and the second capacitance electrode 5 a are formed at a surface of the first interlayer insulating layer 42 on the pixel electrode 9 a side, and then collectively patterned to form the capacitance element 55. Next, after the insulating film 47 is formed, anisotropic etching is performed on the insulating film 47, and the insulating film 47 overlapping with the first interlayer insulating layer 42 and the second capacitance electrode 5 a is removed. Anisotropic etching is further performed on the insulating film 47, thereby exposing a side surface of the second capacitance electrode 5 a. During such etching, the first interlayer insulating layer 42 acts as an etching stopper. As a result, as illustrated in FIG. 7, the insulating film 47 remains as a side wall covering the side surface of the first capacitance electrode 4 a and the side surface of the dielectric film 40, while exposing the side surface of the second capacitance electrode 5 a.

In addition, in a surface of the first interlayer insulating layer 42 on the pixel electrode 9 a side, a region exposed from the insulating film 47 and the capacitance element 55 becomes a recessed portion 42 c recessed from a region overlapping with the insulating film 47 and the capacitance element 55 toward the semiconductor layer 31 a side. Thus, after a light shielding layer is formed, and the light shielding layer is patterned to form the light shielding layer 2 a, the second portion 2 a 2 that protrudes toward the semiconductor layer 31 a side from the surface 4 a 0 on the semiconductor layer 31 a side of the first capacitance electrode 4 a to a position contacting a bottom of the recessed portion 42 c, is formed at the light shielding layer 2 a. In addition, a dimension dl of the second portion 2 a 2 that protrudes from the surface 4 a 0 on the semiconductor layer 31 a side of the first capacitance electrode 4 a toward the semiconductor layer 31 a side is equal to a depth of the recessed portion 42 c. Accordingly, the dimension d1 is a dimension equal to a thickness d2 of a portion of the second capacitance electrode 5 a that protrudes from the insulating film 47 to the pixel electrode 9 a side, or a dimension greater than the thickness d2 of the portion of the second capacitance electrode 5 a that protrudes from the insulating film 47 to the pixel electrode 9 a side.

As can be seen from FIG. 4, a width in the second direction Y of the light shielding layer 2 a is greater than a width in the second direction Y of the first element portion 551, and is less than a width in the second direction Y of the scan line 3 a.

Note that, during the process described above or after the process described above, the dielectric film 40 and the second capacitance electrode 5 a are removed by etching from a position of the first capacitance electrode 4 a where the contact hole 43 b is to be formed.

6. Main Effects of the Present Exemplary Embodiment

As described above, in the electro-optical device 100 of the present exemplary embodiment, the conductive light shielding layer 2 a is provided at the first substrate 10 between the second capacitance electrode 5 a and the second interlayer insulating layer 43, in the layer between the second capacitance electrode 5 a and the pixel electrode 9 a. The light shielding layer 2 a includes the second portion 2 a 2 that protrudes from the end portion in the second direction Y of the first portion 2 a 1 through the side of the first capacitance electrode 4 a toward both the sides in the width direction of the semiconductor layer 31 a. Thus, of light incident on the first substrate 10 from the second substrate 20 side, light that attempts to proceed toward the semiconductor layer 31 a through between the gate electrode 8 a and the capacitance element 55 can be shielded by the second portion 2 a 2 of the light shielding layer 2 a. Therefore, incidence of light on the semiconductor layer 31 a is suppressed. In particular, because the second portion 2 a 2 protrudes toward the semiconductor layer 31 a from the surface 4 a 0 on the semiconductor layer 31 a side of the first capacitance electrode 4 a, so incidence of light on the semiconductor layer 31 a can be further suppressed.

In addition, because the light shielding layer 2 a is a film different from the second capacitance electrode 5 a, structure that does not generate a short circuit between the first capacitance electrode 4 a and the second capacitance electrode 5 a can be employed. More specifically, the light shielding layer 2 a is electrically coupled to the second capacitance electrode 5 a, but the side wall insulating film 47 is interposed between the light shielding layer 2 a and the first capacitance electrode 4 a. Therefore, even when the light shielding layer 2 a is provided, a short circuit is not generated between the first capacitance electrode 4 a and the second capacitance electrode 5 a.

In addition, the width in the second direction Y of the light shielding layer 2 a is greater than the width in the second direction Y of the first element portion 551, and is less than the width in the second direction Y of the scan line 3 a, so even when the light shielding layer 2 a is formed, a pixel opening ratio will not be reduced.

Furthermore, light incident from the second substrate 20 side is shielded by the data line 6 a, the relay electrode 6 c, the capacitance line 7 a, and the like provided on the second substrate 20 side with respect to the semiconductor layer 31 a, so incidence on the semiconductor layer 31 a is suppressed. Further, even when light emitted from the first 10 side is incident again from the first 10 side, the light is shielded by the scan line 3 a provided on the substrate body 19 side with respect to the semiconductor layer 31 a, and thus incidence on the semiconductor layer 31 a is suppressed. In addition, light traveling in the second direction Y intersecting the semiconductor layer 31 a is shielded by the light shielding conductive film formed by the light shielding layer 82 a inside the contact hole 41 g that electrically couples the gate electrode 8 a and the scan line 3 a, so incidence on the semiconductor layer 31 a is suppressed. In particular, in the present exemplary embodiment, by providing the second low concentration region 31 f between the channel region 31 c and the second region 31 e, an off leakage current of the transistor 30 is reduced, and the contact hole 41 g is provided along at least the second low concentration region 31 f. Thus, light traveling in the second direction Y intersecting the semiconductor layer 31 a toward the second low concentration region 31 f can be shielded by the gate electrode 8 a inside the contact hole 41 g. Therefore, incidence of light on the second low concentration region 31 f is efficiently suppressed. Thus, the transistor 30 can sufficiently exhibit characteristics due to LDD structure.

Further, the gate electrode 8 a includes the conductive polysilicon film 81 a and the light shielding layer 82 a, and the light shielding layer 82 a is provided along the side surface of the contact hole 41 g. Therefore, the gate electrode 8 a has a high light shielding property.

Exemplary Embodiment 2

FIG. 12 is an explanatory diagram of the electro-optical device 100 according to Exemplary Embodiment 2 of the present disclosure. FIG. 12 is an enlarged plan view illustrating a vicinity of the transistor 30. FIG. 13 is the A2-A2′ cross-sectional view of FIG. 12. FIG. 14 is the B2-B2′ cross-sectional view of FIG. 12. FIG. 15 is the C2-C2′ cross-sectional view of FIG. 12. Note that basic configurations in this exemplary embodiment are the same as in Exemplary Embodiment 1, and thus, common portions are denoted by the same reference signs and a description of the common portions will be omitted.

As illustrated in FIG. 12 to FIG. 15, in the present exemplary embodiment as well, similar to Exemplary Embodiment 1, the capacitance element 55 including the first capacitance electrode 4 a, the dielectric film 40, and the second capacitance electrode 5 a is provided between the first interlayer insulating layer 42 and the second interlayer insulating layer 43 on an upper layer side of the transistor 30, and the first element portion 551 of the capacitance element 55 overlaps with the semiconductor layer 31 a in plan view. The first capacitance electrode 4 a and the second capacitance electrode 5 a are each formed of a conductive polysilicon film.

The first substrate 10 is provided with a conductive light shielding layer including a first portion 6 c 1 overlapping in plan view with the second capacitance electrode 5 a in a layer between the first element portion 551 of the second capacitance electrode 5 a and the pixel electrode 9 a. In the present exemplary embodiment, the light shielding layer is the light shielding relay electrode 6 c configured by the same layer as the data line 6 a, and the relay electrode 6 c is electrically coupled to the capacitance line 7 a. The second interlayer insulating layer 43 is formed between the second capacitance electrode 5 a and the relay electrode 6 c, the relay electrode 6 c is electrically coupled to the second capacitance electrode 5 a via the contact hole 43 c that extends the second interlayer insulating layer 43.

As illustrated in FIG. 15, the relay electrode 6 c includes a second portion 6 c 2 that protrudes from an end portion of the first portion 6 c 1 in the second direction Y toward the semiconductor layer 31 a side through a side of the second capacitance electrode 5 a. In the present exemplary embodiment, the second portion 6 c 2 protrudes through a side of the second capacitance electrode 5 a toward both sides in a width direction of the semiconductor layer 31 a. Here, an end portion of the second portion 6 c 2 protrudes from a surface 5 a 0 on the semiconductor layer 31 a side of the second capacitance electrode 5 a toward the semiconductor layer 31 a side. Further, an insulating film covering a side surface of the first capacitance electrode 4 a is provided at the first substrate 10, and the second portion 6 c 2 overlaps with the insulating film from a side opposite the first capacitance electrode 4 a. In the present exemplary embodiment, the insulating film is the second interlayer insulating layer 43. The second interlayer insulating layer 43 extends from between the second capacitance electrode 5 a and the relay electrode 6 c with a substantially constant thickness so as to cover the side surface of the first capacitance electrode 4 a, and the second portion 6 c 2 overlaps with the second interlayer insulating layer 43 from a side opposite the first capacitance electrode 4 a.

In a manufacturing process of the electro-optical device 100 having such structure, the first capacitance electrode 4 a, the dielectric film 40, and the second capacitance electrode 5 a are formed at a surface of the first interlayer insulating layer 42 on the pixel electrode 9 a side, and then collectively patterned to form the capacitance element 55. In addition, of the first capacitance electrode 4 a, the dielectric film 40 and the second capacitance electrode 5 a are removed by etching from a position where the contact hole 43 b is to be formed.

Next, after the second interlayer insulating layer 43 is formed, the contact hole 43 c and the like are formed in the second interlayer insulating layer 43. Next, after a light shielding conductive film is formed, the light shielding conductive film is patterned to form the relay electrode 6 c. At this time, the data line 6 a and the relay electrode 6 b are formed simultaneously. In the present exemplary embodiment, a width in the second direction Y of the relay electrode 6 c is greater than a width in the second direction Y of the first element portion 551, and is less than a width in the second direction Y of the scan line 3 a.

In the electro-optical device 100 configured in this manner as well, in the first substrate 10, the relay electrode 6 c as a light shielding layer is provided with the second portion 6 c 2 that protrudes from an end portion of the first portion 6 c 1 in the second direction Y toward both sides in a width direction of the semiconductor layer 31 a through a side of the second capacitance electrode 5 a, in a layer between the second capacitance electrode 5 a and the pixel electrode 9 a. Thus, of light incident on the first substrate 10 from the second substrate 20 side, light that attempts to proceed toward the semiconductor layer 31 a through between the gate electrode 8 a and the capacitance element 55 can be shielded by the second portion 6 c 2 of the relay electrode 6 c. Therefore, incidence of light on the semiconductor layer 31 a is suppressed.

Other Exemplary Embodiments

In the exemplary embodiments described above, the semiconductor layer 31 a extends so as to overlap with the scan line 3 a in plan view, but the present disclosure may be applied when the semiconductor layer 31 a extends so as to overlap in plan view with the data line 6 a.

In the exemplary embodiments described above, the data line 6 a, the relay electrode 6 c, and the capacitance line 7 a constitute a light shielding member overlapping in plan view with the semiconductor layer 31 a from the pixel electrode 9 a side, but at least one of the first capacitance electrode 4 a and the second capacitance electrode 5 a may be a light shielding electrode, and a light shielding member overlapping in plan view with the semiconductor layer 31 a from the pixel electrode 9 a side may be constituted.

In the above-described exemplary embodiments, the electro-optical device 100 has been described as an example in which light source light is incident from the second substrate 20 side, but the present disclosure may also be applied to the electro-optical device 100 in which light source light is incident from the first substrate 10 side. Further, in the above-described exemplary embodiments, the case has been illustrated in which the electro-optical device 100 is the transmissive liquid crystal device, however, the present disclosure may be applied to a case in which the electro-optical device 100 is a reflection-type liquid crystal device. Further, the present disclosure may be applied to a case in which the electro-optical device 100 is an organic electroluminescence display device.

Installation Example to Electronic Apparatus

An electronic apparatus using the electro-optical device 100 according to the above-described exemplary embodiments will be described below. FIG. 16 is a schematic configuration view of a projection-type display device using the electro-optical device 100 to which the present disclosure is applied. Illustration of an optical element such as a polarizing plate is omitted in FIG. 16. A projection-type display device 2100 illustrated in FIG. 16 is an example of an electronic apparatus using the electro-optical device 100. The projection-type display device 2100, in which the electro-optical device 100 is used as a light valve, can conduct high-definition and bright display without making the apparatus large. As illustrated in this figure, a light source unit 2102 including a lamp unit and the like including a white light source such as a halogen lamp is provided inside the projection-type display device 2100. Projection light emitted from the light source unit 2102 is split into three primary colors of R (red), G (green), and B (blue) by three mirrors 2106 and two dichroic mirrors 2108 installed inside. The split incident light is guided to light valves 100R, 100G, and 100B corresponding to each of the primary colors, and then modulated. Note that since the light of the B color has a long optical path as compared to the other light of the R color and the G color, the light of the B color is guided via a relay lens system 2121 including an incidence lens 2122, a relay lens 2123, and an emission lens 2124 to prevent a loss due to the long optical path of the light of the B color.

The light modulated by each of the light valves 100R, 100G, and 100B is incident on a dichroic prism 2112 from three directions. Then, at the dichroic prism 2112, the light of the R color and the light of the B color are reflected at 90 degrees, and the light of the G color is transmitted. Accordingly, respective images of the primary colors are synthesized, and subsequently a color image is projected on a screen 2120 by a projection optical system 2114.

Other Projection-Type Display Devices

Note that the projection-type display device may include a configuration in which an LED light source or the like configured to emit light of each color is used as a light source unit and the light of each color emitted from the LED light source is supplied to another liquid-crystal device.

Other Electronic Apparatuses

The electronic apparatus including the electro-optical device 100 to which the present disclosure is applied is not limited to the projection-type display device 2100 of the above-described exemplary embodiment. Examples of the electronic apparatus may include a projection-type head up display, a direct-view-type head mounted display, a personal computer, a digital still camera, and a liquid crystal television. 

What is claimed is:
 1. An electro-optical device, comprising: a substrate body; a pixel electrode; a transistor including a semiconductor layer in a layer between the substrate body and the pixel electrode; a capacitance element including a first capacitance electrode overlapping with the semiconductor layer, the first capacitance electrode being in a layer between the transistor and the pixel electrode, and a second capacitance electrode overlapping with the first capacitance electrode, the second capacitance electrode being in a layer between the first capacitance electrode and the pixel electrode; and a light shielding layer that includes a first portion overlapping with the second capacitance electrode between the second capacitance electrode and the pixel electrode, and a second portion protruding from an end portion of the first portion, through a side of the first capacitance electrode toward the substrate body side, the first portion being electrically coupled to the second capacitance electrode.
 2. The electro-optical device according to claim 1, wherein the second portion protrudes from an end portion of the first portion through a side of the first capacitance electrode toward both sides in a width direction of the semiconductor layer.
 3. The electro-optical device according to claim 1, comprising: an insulating layer covering a side surface of the first capacitance electrode, wherein the second portion overlaps with the insulating layer from a side opposite the first capacitance electrode.
 4. The electro-optical device according to claim 3, comprising: a dielectric layer between the first capacitance electrode and the second capacitance electrode, wherein the insulating layer is a side wall not overlapping in plan view with the second capacitance electrode, and covering a side surface of the first capacitance electrode and a side surface of the dielectric layer, and the first portion is stacked on a surface of the second capacitance electrode on the pixel electrode side.
 5. The electro-optical device according to claim 4, wherein the second portion protrudes from a surface of the first capacitance electrode on the substrate body side toward the substrate body side.
 6. The electro-optical device according to claim 5, comprising: a first interlayer insulating layer provided in a layer between the transistor and the pixel electrode, wherein a region exposed from the insulating layer and the capacitance element, of a surface of the first interlayer insulating layer on the pixel electrode side, is a recessed portion recessed from a region overlapping with the insulating layer and the capacitance element toward the substrate body side, and the second portion protrudes from a surface of the first capacitance electrode on the substrate body side toward the substrate body side up to a position in contact with a bottom of the recessed portion.
 7. The electro-optical device according to claim 6, wherein a dimension of the second portion protruding from a surface of the first capacitance electrode on the substrate body side toward the substrate body side, is a dimension equal to a thickness of a portion of the second capacitance electrode protruding from the side wall toward the pixel electrode side, or a dimension greater than a portion of the second capacitance electrode protruding from the side wall toward the pixel electrode side.
 8. The electro-optical device according to claim 3, wherein the insulating layer is a second interlayer insulating layer extending from a portion between the second capacitance electrode and the light shielding layer so as to cover a side surface of the first capacitance electrode, and the first portion is electrically coupled to the second capacitance electrode via a contact hole extending through the second interlayer insulating layer.
 9. The electro-optical device according to claim 8, wherein the light shielding layer is a relay electrode for applying a constant potential to the second capacitance electrode.
 10. The electro-optical device according to claim 1, comprising: a scan line extending in a first direction in a layer between the substrate body and the semiconductor layer; and a data line extending in a second direction intersecting the first direction in a layer between the second capacitance electrode and the pixel electrode, wherein the semiconductor layer extends in the first direction so as to overlap with the scan line, and the capacitance element includes a first element portion including the second portion protruding toward both sides in the second direction of the semiconductor layer.
 11. The electro-optical device according to claim 10, wherein a width in the second direction of the light shielding layer is greater than a width of the first element portion in the second direction and is less than a width of the scan line in the second direction.
 12. The electro-optical device according to claim 11, wherein the capacitance element includes a second element portion extending in the second direction from a portion where the first element portion overlaps with the data line.
 13. The electro-optical device according to claim 10, wherein on a side of the semiconductor layer in the second direction, a contact hole is provided inside which a light shielding conductive layer electrically coupling a gate electrode of the transistor to the scan line is provided.
 14. An electronic apparatus, comprising: the electro-optical device according to claim
 1. 